The present disclosure relates generally to nanowire arrays, and more particularly to forming a substantially non-uniform array of nanowires.
Nanowires are generally formed in uniform arrays because nanowires to date have been known to grow at the same rate when the nanoparticles catalyzing the nanowires are of uniform size. Extensive effort has been expended to form nanoparticles with a narrow size distribution so that the properties of the nanowires in an array are uniform. In some instances, however, an array of nanowires with lengths that vary in a controlled manner from one nanowire to another are desired. In order to achieve non-uniform arrays, the lengths of selected large (at least micron scale) regions of nanowires are reduced to a desirable size by, for example, etching or oxidation followed by etching. These additional steps may add to the complexity and expense of the formation process.
As such, it would be desirable to provide a method for forming a non-uniform array of nanowires during nanowire growth, where the method allows for selective control of individual nanowire growth rate, length, and diameter.